Transflective liquid crystal display device having color filter-on-thin film transistor (COT) structure and method of fabricating the same

ABSTRACT

A transflective liquid crystal display device includes a thin film transistor disposed at a corner of a pixel region, the thin film transistor including a gate electrode, a semiconductor layer, a source electrode, and a drain electrode, a reflector disposed in the pixel region and spaced apart from the thin film transistor, the reflector formed of the same material as one of the gate, source, and drain electrodes, a color filter disposed within the pixel region, the color filter having one of red, green, and blue colors, a black matrix over the thin film transistor along color filter borders of adjacent pixel regions, and a pixel electrode formed of a transparent conductive material adjacent to the color filter, the pixel electrode having a first end portion contacting the drain electrode of the thin film transistor, wherein the pixel region is divided into a reflective portion including the reflector and a transmissive portion absent of the reflector.

[0001] The present invention claims the benefit of Korean PatentApplication No. P2003-0012615 filed in Korea on Feb. 28, 2002, which ishereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a liquid crystal display (LCD)device, and more particularly, to an array substrate having a colorfilter-on-thin film transistor (COT) structure.

[0004] 2. Discussion of the Related Art

[0005] In general, since flat panel display devices are thin, lightweight, and have low power consumption, they are used in portabledisplay devices. Among the various types of flat panel display devices,liquid crystal display (LCD) devices are commonly used in laptopcomputers and desktop computer monitors because of their superiorresolution, color image display, and display quality.

[0006] In the LCD devices, optical anisotropy and polarizationcharacteristics of liquid crystal molecules are utilized to generateimages, wherein liquid crystal molecules have specific alignmentdirections that result from their inherent properties. The specificalignment directions of the liquid crystal molecules may be modified byapplication of an electric field. Thus, due to the optical anisotropy,incident light is refracted according to the alignment of the liquidcrystal molecules.

[0007] The LCD devices include upper and lower substrates each havingelectrodes that are spaced apart and face each other, and a liquidcrystal material interposed between the upper and lower substrates.Accordingly, when a voltage is applied to each of the electrodes of theupper and lower substrates, the alignment direction of the liquidcrystal molecules is changed in accordance with the applied voltage,thereby displaying images. By controlling the applied voltage, the LCDdevice provides various light transmittances to display image data.

[0008] The liquid crystal display (LCD) devices are commonly employed inoffice automation (OA) and video equipment due to their light weight,slim design, and low power consumption. Among the different types of LCDdevices, active matrix LCDs (AM-LCDs), which have thin film transistorsand pixel electrodes arranged in a matrix form, provide high resolutionand superiority in displaying moving images.

[0009] In general, the LCD device displays an image using light emittedfrom a backlight device that is positioned under the LCD panel. However,the LCD only utilizes 3˜8% of the incident light generated from thebacklight device, thereby providing inefficient optical modulation.Thus, the LCD device using the backlight device usually consumes asignificant amount of electrical energy in order to provide light ofreasonable brightness.

[0010] In order to overcome the high power consumption, there is a needfor a transflective LCD device that utilizes ambient light andartificial light generated from the backlight device. Specifically, thetransflective LCD device may be used during daytime hours as well asnighttime because the transflective LCD device can be changed to operatein one of a transmissive mode and a reflective mode depending on thedesired condition of operation. The transflective LCD device includes areflector within each pixel where a transparent electrode mainly existsto electrically communicate with the transparent electrode, and thenfunction as a pixel electrode with the transparent electrode.

[0011]FIG. 1 is a cross sectional view of a transflective liquid crystaldisplay device according to the related art. In FIG. 1, first and secondsubstrates 10 and 50 are spaced apart and face each other, wherein afront surface of the first substrate 10 includes a thin film transistorT having a gate electrode 12, a semiconductor layer 16, and source anddrain electrodes 18 and 20. In addition, a gate insulation layer 14 isformed on the first substrate 10 and is interposed between the gateelectrode 12 and the semiconductor layer 16 in the thin film transistorT, and a first passivation layer 22 is formed on the gate insulationlayer 14 to cover the thin film transistor T. A reflector 24 thatreflects incident light is formed on the passivation layer 22 within anarea where a reflective portion is defined within a pixel region P. Asecond passivation layer 26 is formed over the first substrate 10 tocover the reflector 24, and the first and second passivation layers 22and 26 and the reflector 24 together include a drain contact hole 28that exposes a portion of the drain electrode 20. A pixel electrode 30is disposed on the second passivation layer 26 within the pixel regionP, which is formed of a transparent conductive material, and contactsthe drain electrode 20 through the drain contact hole 28. In addition, adata line 21 is formed on the gate insulation layer 14 and is connectedwith the source electrode 18. Although not shown in FIG. 1, a gate lineis formed with the gate electrode 12 on the first substrate 10 anddefines the pixel region P while perpendicularly crossing the data line21.

[0012] In FIG. 1, a black matrix 52 is formed on a rear surface of thesecond substrate 50 to correspond in position to the data line 21 andthe gate line (not shown). A color filter layer 54 having red, green,and blue colors is formed on the rear surface of the second substrate 50while covering the black matrix 52. In addition, a common electrode 56is disposed on a rear surface of the color filter layer 54, and isformed of the same material as the pixel electrode 30, such as atransparent conductive material. Moreover, a liquid crystal layer 70 isinterposed between the pixel electrode 30 and the common electrode 56.Accordingly, the pixel region P is divided into a reflective portion,which corresponds to the reflector 24, and a transmissive portion, whichcorresponds to the pixel electrode except for the reflective portion.

[0013] The reflective LCD device, as shown in FIG. 1, is fabricated bysequential processes including: a gate process (forming the gateelectrode and line); an active process (forming the semiconductorlayer); a source/drain process (forming the source and drain electrodesand the data line); a first contact hole process (forming the firstpassivation layer); a reflective process (forming the reflector); asecond contact hole process (forming the second passivation layer); atransmissive process (forming the pixel electrode); a black matrixprocess (forming the black matrix); a color filter process (forming thered, green, and blue color filters); a common electrode process (formingthe common electrode); and an aligning process (attaching the first andsecond substrates and interposing the liquid crystal therebetween).Accordingly, the fabrication processes for manufacturing the reflectiveLCD device of FIG. 1 is extremely complicated. In addition, a secondcontact hole process for forming the second passivation layer 26 may benecessary since the second passivation layer 26 prevents electrochemicalreaction between the reflector 24 and the pixel electrode 30.

[0014] The reflector 24 commonly includes aluminum (Al) or silver (Ag)material having superior reflectivity, and the pixel electrode 30 iscommonly formed of the transparent conductive material, such asindium-tin-oxide (ITO). When the reflector 24 and the pixel electrode 30are dipped together into a solution, the indium ion (In³⁺) of ITOobtains electrons and becomes an indium (In) metal and aluminum (Al) ofthe reflector loses electrons and becomes the aluminum ion (Al³⁺). As aresult, the transparent conductive material (ITO) is damaged, therebylosing its transparency and becomes darkened. Therefore, the secondpassivation layer 26 is necessary between the reflector 24 and the pixelelectrode 30 in order to isolate the reflector 24 from the pixelelectrode 30.

[0015] The transflective LCD device of FIG. 1 may be operated in boththe reflective mode and the transmissive mode. In the reflective mode,incident light L1 is reflected from the reflector 24 and is directedtoward the second substrate 50, whereby the incident light encountersand passes through the color filter layer 54 twice. Conversely,artificial light L2 generated from the backlight device (not shown) onlypasses through the color filter layer 54 once. Accordingly, the light L1and L2 colored by the color filter layer 54 to display color images havedifferent light paths in the reflective mode and the transmissive mode,respectively. Because of these different light paths, color reproductionin the reflective portion is different from that in the transmissiveportion even though the same color filter is utilized.

[0016] To overcome the problem of different color reproduction, thecolor filter in the reflective portion is formed to have a one-halfthickness than that in the transmissive portion. Thus, the light path ofincident light is shortened when the incident light passes through thecolor filter in the reflective mode.

[0017]FIG. 2 is a partial cross sectional view of a transflective LCDdevice according to the related art. In FIG. 2, a transparent interlayer82 is formed on a rear surface of a upper substrate 80, and a colorfilter 84 is formed on the rear surface of the upper substrate 80 tocover the transparent interlayer 82. The transparent interlayer 82corresponds to a reflective portion where a reflector 94 is disposed. Afirst portion 84 a of the color filter 84 has a first thickness d1 thatcorresponds to the reflective portion, and a second portion 84 b of thecolor filter 84 has a second thickness d2 that corresponds to thetransmissive portion. Since the transparent interlayer 82 is formedwithin the reflective portion between the substrate 80 and the colorfilter 84, the first thickness d1 is less than the second thickness d2by as much as the thickness of the transparent interlayer 82. Whenincident light LL1 is reflected on the reflector 94, the incident lightLL1 transits twice through the first portion 84 a of the color filter 84whose thickness is almost one-half that of the second portion of thecolor filter 84. Therefore, the light path of incident light LL1 is thesame as that of artificial light LL2 that passes through the secondportion 84 b.

[0018] However, since the transparent interlayer 82 is provided to lowerthe thickness of the first portion 84 a of the color filter 84,supplementary processes for forming the transparent interlayer 82 arerequired. Second, it is essential to form the color filter 84 to beplanar in order to form a common electrode on its surface. Accordingly,much more complicated process steps are necessary for the transflectiveLCD device, and fabrication costs of transflective LCD device willincrease.

SUMMARY OF THE INVENTION

[0019] Accordingly, the present invention is directed to an arraysubstrate having a color filter-on-thin film transistor (COT) structurefor a transflective liquid crystal display device that substantiallyobviates one or more of the problems due to limitations anddisadvantages of the related art.

[0020] An object of the present invention is to provide a transflectiveliquid crystal display device having a reduced number of processingsteps.

[0021] Another object of the present invention is to provide atransflective liquid crystal display device having increased colorreproduction.

[0022] Another object of the present invention is to provide a method offabricating a transflective liquid crystal display device havingsimplified and stabilized fabricating processes to increasemanufacturing yield.

[0023] Additional features and advantages of the invention will be setforth in the description which follows, and in part will be apparentfrom the description, or may be learned by practice of the invention.The objectives and other advantages of the invention will be realizedand attained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

[0024] To achieve these and other advantages of the present invention,as embodied and broadly described, a transflective liquid crystaldisplay device includes a thin film transistor disposed at a corner of apixel region, the thin film transistor including a gate electrode, asemiconductor layer, a source electrode, and a drain electrode, areflector disposed in the pixel region and spaced apart from the thinfilm transistor, the reflector formed of the same material as one of thegate, source, and drain electrodes, a color filter disposed within thepixel region, the color filter having one of red, green, and bluecolors, a black matrix over the thin film transistor along color filterborders of adjacent pixel regions, and a pixel electrode formed of atransparent conductive material adjacent to the color filter, the pixelelectrode having a first end portion contacting the drain electrode ofthe thin film transistor, wherein the pixel region is divided into areflective portion including the reflector and a transmissive portionabsent of the reflector.

[0025] In another aspect, a transflective liquid crystal display deviceincludes a substrate, a gate electrode disposed in a thin filmtransistor region on the substrate, a first buffer pattern disposed in apixel region on the substrate and spaced apart from the gate electrode,a gate insulation layer formed on the substrate to cover the gateelectrode and the first buffer pattern, a semiconductor layer on thegate insulation layer over the gate electrode, a second buffer patternformed of the same material as the semiconductor layer and formed duringthe same time as formation of semiconductor layer, the second bufferpattern disposed above the first buffer pattern in the pixel region,source and drain electrodes formed on the semiconductor layer and spaceapart from each other, a reflector on the second buffer pattern, thereflector formed of the same material as the source and drainelectrodes, a color filter disposed within the pixel region and havingone of red, green, and blue colors, a black matrix formed above a thinfilm transistor in the thin film transistor region, the thin filmtransistor includes the gate electrode, the semiconductor layer, and thesource and drain electrodes, the black matrix covering the thin filmtransistor except for a portion of the drain electrode and borderingadjacent color filters of neighboring pixel regions, and a pixelelectrode disposed in the pixel region and formed of a transparentconductive material, the pixel electrode adjacent to the color filterand having a first end portion contacting the drain electrode of thethin film transistor, wherein the pixel region is divided into areflective portion that includes the reflector and a transmissiveportion that is absent of the reflector, the color filter has a firstthickness in the transmissive portion and a second thickness in thereflective portion, and the first thickness is larger than the secondthickness.

[0026] In another aspect, a transflective liquid crystal display deviceincludes a substrate, a gate electrode disposed in a thin filmtransistor region on the substrate, a first buffer pattern disposed in apixel region on the substrate and spaced apart from the gate electrode,a gate insulation layer formed on the substrate to cover the gateelectrode and the first buffer pattern, a semiconductor layer on thegate insulation layer over the gate electrode, a second buffer patterndisposed above the first buffer pattern in the pixel region and formedof the same material as the semiconductor layer and formed during thesame time as the semiconductor layer, source and drain electrodes formedon the semiconductor layer, the source and drain electrodes have thesame planar shape with the semiconductor layer except for a spacebetween the source and drain electrodes, a reflector on the secondbuffer pattern, the reflector is formed of the same material as thesource and drain electrodes and has the same planar shape as the secondbuffer pattern, a color filter disposed within the pixel region, andhaving one of red, green, and blue colors, a black matrix formed above athin film transistor in the thin film transistor region, the thin filmtransistor includes the gate electrode, the semiconductor layer, and thesource and drain electrodes, the black matrix covering the thin filmtransistor except for a portion of the drain electrode and bordersadjacent color filters of the neighboring pixel regions, a passivationlayer covering the thin film transistor and the reflector, thepassivation layer exposing an edge portion of the drain electrode, and apixel electrode disposed in the pixel region and formed of a transparentconductive material, the pixel electrode adjacent to the color filterand contacting the edge portion of the drain electrode of the thin filmtransistor, wherein the pixel region is divided into a reflectiveportion having the reflector and a transmissive portion absent of thereflector, the color filter has a first thickness in the transmissiveportion and a second thickness in the reflective portion, and the firstthickness is larger than the second thickness.

[0027] In another aspect, a transflective liquid crystal display deviceincludes a substrate, a gate electrode disposed in a thin filmtransistor region on the substrate, a first buffer pattern disposed in apixel region on the substrate and spaced apart from the gate electrode,a gate insulation layer formed on the substrate to cover the gateelectrode and the first buffer pattern, a semiconductor layer on thegate insulation layer over the gate electrode, a second buffer patternformed of the same material as the semiconductor layer and formed at thesame time as the semiconductor layer, the second buffer pattern disposedabove the first buffer pattern in the pixel region, source and drainelectrodes formed on the semiconductor layer and space apart from eachother, the source and drain electrodes have the same planar shape withthe semiconductor layer except for a space between the source and drainelectrodes, a reflector on the second buffer pattern, the reflector isformed of the same material as the source and drain electrodes and hasthe same planar shape as the second buffer pattern, a thin filmtransistor disposed in the thin film transistor region, the thin filmtransistor including the gate electrode, the semiconductor layer, andthe source and drain electrodes, a passivation layer covering the thinfilm transistor and the reflector, the passivation layer exposing anedge portion of the drain electrode, and a color filter disposed over anentire surface of the substrate on the passivation layer, the colorfilter having one of red, green, and blue colors and having a draincontact hole exposing the edge portion of the drain electrode, and apixel electrode formed of a transparent conductive material and disposedover the color filter in the pixel region, the pixel electrodecontacting the edge portion of the drain electrode through the draincontact hole, wherein the pixel region is divided into a reflectiveportion having the reflector and a transmissive portion absent of thereflector, the color filter has a first thickness in the transmissiveportion and a second thickness in the reflective portion, and the firstthickness is larger than the second thickness.

[0028] In another aspect, a method of fabricating a transflective liquidcrystal display device includes forming a gate electrode and a firstbuffer pattern on a substrate using a first mask process, forming a gateinsulation layer on the substrate to cover the gate electrode and thefirst buffer pattern, forming a pure amorphous silicon layer, a dopedamorphous silicon layer, and a metal layer in sequence on the gateinsulation layer, patterning the pure amorphous silicon layer, the dopedamorphous silicon layer, and the metal layer simultaneously using asecond mask process to form a semiconductor layer over the gateelectrode, source and drain electrodes on the semiconductor layer, asecond buffer pattern over the first buffer pattern, and a reflector onthe second buffer pattern, forming a first passivation layer on the gateinsulation layer to cover the source and drain electrodes and thereflector, forming a black matrix on the first passivation layer tocover the gate electrode, the source electrode, and the drain electrodeexcept for an edge portion of the drain electrode, forming a secondpassivation layer on the first passivation layer to cover the blackmatrix, patterning the first and second passivation layers and the gateinsulation layer to form an opening that exposes the edge portion of thedrain electrode and portions of the substrate, forming a firsttransparent conductive layer over an entire surface of the substrate,the first transparent conductive layer contacting the exposed edgeportion of the drain electrode and the exposed portion of the substrate,forming a color filter on the first transparent conductive layer in apixel region to cover the reflector, the color filter having one of red,green, and blue colors, forming a second transparent conductive layer onthe color filter and on an exposed portion of the first transparentconductive layer, patterning the first and second transparent conductivelayers simultaneously to form first and second transparent pixelelectrodes between where the color filter is interposed.

[0029] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory and are intended to provide further explanation of theinvention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiments of theinvention and together with the description serve to explain theprinciple of the invention.

[0031]FIG. 1 is a cross sectional view of a transflective liquid crystaldisplay device according to the related art;

[0032]FIG. 2 is a partial cross sectional view of a transflective LCDdevice according to the related art;

[0033]FIG. 3 is a cross sectional view of an exemplary transflectiveliquid crystal display device having a color filter-on-thin filmtransistor structure according to the present invention;

[0034]FIG. 4 is a cross sectional view of another exemplarytransflective liquid crystal display device having a colorfilter-on-thin film transistor structure according to the presentinvention;

[0035]FIG. 5 is a cross sectional view of another exemplarytransflective liquid crystal display device having a colorfilter-on-thin film transistor structure according to the presentinvention;

[0036]FIG. 6 is a cross sectional view of another exemplarytransflective liquid crystal display device having a colorfilter-on-thin film transistor structure according to a the presentinvention;

[0037]FIGS. 7A to 7K are plan views of exemplary reflective andtransmissive portions within a pixel region of a transflective liquidcrystal display device according to the present invention;

[0038]FIG. 8 is a cross sectional view of an exemplary transflectiveliquid crystal device having a color filter-on-thin film transistorstructure and buffer patterns according to the present invention;

[0039]FIG. 9 is a cross sectional view of another exemplarytransflective liquid crystal device having a color filter-on-thin filmtransistor structure and buffer patterns according to the presentinvention;

[0040]FIGS. 10A to 10E are cross sectional views of another exemplarytransflective LCD devices each having a color filter-on-thin filmtransistor structure and buffer patterns according to the presentinvention; and

[0041]FIGS. 11A to 11H are cross sectional views of an exemplaryfabrication process of a transflective liquid crystal display deviceaccording to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings.

[0043]FIG. 3 is a cross sectional view of an exemplary transflectiveliquid crystal display device having a color filter-on-thin filmtransistor structure according to the present invention. In FIG. 3, agate electrode 112 may be formed on a substrate 110, and a reflector 114may be formed on the substrate 110 within a pixel region P. Thereflector 114 may be spaced apart from the gate electrode 112 such thatan area where the reflector is disposed may become a reflective portion.The gate electrode 112 and the reflector 114 may be formed of the samematerial during the same fabrication process. In addition, a gateinsulating layer 116 may be formed on the substrate 110 to cover thegate electrode 112 and the reflector 114, and a semiconductor layer 118may be disposed on the gate insulating layer 116, especially above thegate electrode 112. The semiconductor layer 118 may include a firstlayer 118 a of intrinsic amorphous silicon and a second layer 118 b ofextrinsic amorphous silicon. The first layer 118 a may be referred to asan active layer, and a second layer 118 b may be referred to as an ohmiccontact layer. In addition, source and drain electrodes 120 and 122 maybe formed on the semiconductor layer 118, and a data line 124 may beformed on the gate insulating layer 116 to be connected to the sourceelectrode 120. As shown in FIG. 3, an exposed portion of the ohmiccontact layer 118 b between the source and drain electrodes 120 and 122may be removed to expose a portion of the active layer 118 a, therebyforming a channel ch on the active layer 118 a. Accordingly, the gateelectrode 112, the semiconductor layer 118, and the source and drainelectrodes 120 and 122 may constitute a thin film transistor T.

[0044] In FIG. 3, a first passivation layer 124 may be formed on thegate insulating layer 116 over an entire surface of the substrate 110 tocover the thin film transistor T. In addition, a black matrix 126 may beformed on the first passivation layer 124, especially covering the dataline 124 and the thin film transistor T except for a portion of thedrain electrode 122. A second passivation layer 128 may be disposed onthe first passivation layer 124 to cover the black matrix 126, whereinthe first and second passivation layers 124 and 128 may have a draincontact hole that exposes a portion of the drain electrode 122. Next, afirst transparent electrode 130 may be formed on the second passivationlayer 128 within the pixel region P, wherein the first transparentelectrode 130 may contact the drain electrode 122 through the draincontact hole, and may overlap a portion of the black matrix 126.Although not shown, the black matrix 126 may be disposed to correspondto a gate electrode (not shown) so that it defines the pixel region Pwhere a color filter 132 may be disposed, wherein the black matrix 126may function as a border of neighboring color filters. Meanwhile, thefirst passivation layer 128 may be omitted depending on a fabricationprocess of the black matrix and material used to fabricate the blackmatrix. For example, in FIG. 3, the black matrix 126 may be a blackresin.

[0045] In FIG. 3, a color filter 132 having red, green, or blue colorsmay be formed on the first transparent electrode 130 within the pixelregion P, and a second transparent electrode 134 may be formed on colorfilter 132 to contact the first transparent electrode 130, wherein thesecond transparent electrode 134 may completely cover the color filter132. The first and second transparent electrodes 130 and 134 mayconstitute a pixel electrode 136, and may be referred to as a sandwichpixel electrode since the color filter 132 may be interposed between thefirst and second transparent electrodes 130 and 134. Accordingly, thepixel region P may be divided into the reflection portion where thereflector 114 is formed and the transmissive portion where the othertransparent layers are formed.

[0046] According to the exemplary transflective liquid crystal displaydevice of FIG. 3, the color filter and the thin film transistor may bedisposed together over the substrate, thereby providing a high apertureratio. In addition, the reflector may be formed simultaneously withformation of the gate electrode, thereby reducing fabrication processsteps. Moreover, since the insulators may be formed between thereflector and the transparent pixel electrode, additional processes forforming the insulating layer may not be necessary.

[0047]FIG. 4 is a cross sectional view of another exemplarytransflective liquid crystal display device having a colorfilter-on-thin film transistor structure according to the presentinvention. In FIG. 4, a gate electrode 212 may be formed on a substrate210, and a reflector 214 may be formed on the substrate 210 within apixel region P, wherein the reflector 214 may be spaced apart from thegate electrode 212, such that an area where the reflector 214 isdisposed may become a reflective portion. The gate electrode 212 and thereflector 214 together may have a double-layered structure, wherein thegate electrode 212 may have a first metal layer 212 a and a second metallayer 212 b, and the reflector 214 may have a first metal layer 214 aand a second metal layer 214 b. The first metal layers 212 a and 214 amay include metallic material having low electrical resistance, and thesecond metal layers 212 b and 214 b may include metallic material havingexcellent chemical resistance. For example, the first metal layers 212 aand 214 a may include aluminum (Al) and the second metal layers 212 band 214 b may include molybdenum (Mo). A first metal for the firstlayers 212 a and 214 a and a second metal for the second layers 212 band 214 b may be sequentially formed on the substrate 210, and then maybe patterned using simultaneous photolithography processes.

[0048] In FIG. 4, a gate insulating layer 216 may be formed on thesubstrate 210 to cover the gate electrode 212 and the reflector 214, anda semiconductor layer 218 may be disposed on the gate insulating layer216, especially above the gate electrode 212. The semiconductor layer218 may include a first layer 218 a of intrinsic amorphous silicon and asecond layer 218 b of extrinsic amorphous silicon, wherein the firstlayer 218 a may be referred to as an active layer and the second layer218 b may be referred to as an ohmic contact layer. In addition, sourceand drain electrodes 220 and 222 may be formed on the semiconductorlayer 218, and a data line 224 may be formed on the gate insulatinglayer 216 to be connected with the source electrode 220. Then, anexposed portion of the ohmic contact layer 218 b may be removed toexpose a portion of the active layer 218 a between the source and drainelectrodes 220 and 222, thereby forming a channel ch on the active layer218 a. Accordingly, the gate electrode 212, the semiconductor layer 218,and the source and drain electrodes 220 and 222 may constitute a thinfilm transistor T.

[0049] In FIG. 4, a first passivation layer 224 may be formed on thegate insulating layer 216 over an entire surface of the substrate 210 tocover the thin film transistor T, wherein portions of the gateinsulating layer 216 and first passivation layer 224 may be removed toform an opening 218 that exposes the second metal layer 214 b of thereflector 214. Accordingly, the exposed second metal layer 214 b may beeliminated to expose the underlying first metal layer 214 a. The firstmetal layer 214 a of the reflector 214 may be exposed since the firstmetal for the first metal layer 214 a, such as aluminum (Al), may have abetter reflectivity than the second metal for the second metal layer 214b, such as molybdenum (Mo). The process of forming the opening 218 maybe performed at the same time as formation of a drain contact hole thatexposes a portion of the drain electrode 222 through the firstpassivation layer 224. If the second metal layer 214 b is molybdenum(Mo), the gate insulation layer 216, the first passivation layer 224,and the second metal layer 216 b may be simultaneously patternedthroughout the same dry etching process. Thus, an additional process ofremoving the second metal layer 214 b may not be necessary.

[0050] In FIG. 4, a black matrix 226 may be formed on the firstpassivation layer 224, especially covering the data line 224 and thethin film transistor T, except for a portion of the drain electrode 222.In addition, a second passivation layer 228 may be disposed over anentire surface of the substrate 210 to cover the patterned firstpassivation layer 224 and the black matrix 226, wherein the first andsecond passivation layers 224 and 228 may have a drain contact hole thatexposes a portion of the drain electrode 222. A first transparentelectrode 230 may be formed on the second passivation layer 228 withinthe pixel region P, and may contact the drain electrode 222 through thedrain contact hole and may overlap a portion of the black matrix 226.Although not shown, the black matrix 226 may be disposed to correspondto a gate electrode (not shown) so that it defines the pixel region Pwhere a color filter may be disposed, wherein the black matrix 226 mayfunction as a border of neighboring color filters 232. Next, a colorfilter 232 having red, green, or blue color may be formed on the firsttransparent electrode 230 within the pixel region P. A secondtransparent electrode 234 may be formed on color filter 232 to contactthe first transparent electrode 230, wherein the second transparentelectrode 234 may completely cover the color filter 232. Since thesecond transparent electrode 234 may contact the first transparentelectrode 230, it may electrically communicate with the thin filmtransistor T via the first transparent electrode 230. The first andsecond transparent electrodes 230 and 234 may constitute a pixelelectrode that may be referred to as a sandwich pixel electrode sincethe color filter 232 may be interposed between the first and secondtransparent electrodes 230 and 234. Accordingly, the pixel region P maybe divided into the reflection portion where the reflector 214 is formedand the transmissive portion where the other transparent layers areformed.

[0051]FIG. 5 is a cross sectional view of another exemplarytransflective liquid crystal display device having a colorfilter-on-thin film transistor structure according to the presentinvention. In FIG. 5, a gate electrode 312 may be formed on a substrate310, and a gate insulating layer 314 may be formed on the substrate 310to cover the gate electrode 312. In addition, a semiconductor layer 316may be disposed on the gate insulating layer 314, especially coveringthe gate electrode 312, and may include a first layer 316 a of intrinsicamorphous silicon and a second layer 316 b of extrinsic amorphoussilicon. The first layer 316 a may be referred to as an active layer,and a second layer 316 b may be referred to as an ohmic contact layer.

[0052] Next, source and drain electrodes 318 and 320 may be disposed onthe semiconductor layer 316, and a data line 323 may be formed on thegate insulating layer 314 to be connected with the source electrode 318.In addition, a reflector 322 may be formed on the gate insulating layer314 within the pixel region P and may be spaced apart from the drainelectrode 320. Accordingly, an area where the reflector 322 may bedisposed may be defined as a reflective portion. The source electrode318, the drain electrode 320, the reflector 322, and the data line 323may be formed together using the same patterning process and the samemetallic material. Accordingly, an exposed portion of the ohmic contactlayer 316 b between the source and drain electrodes 318 and 320 may beremoved to expose a portion of the active layer 316 a, thereby forming achannel ch on the active layer 316 a. Thus, the gate electrode 312, thesemiconductor layer 316, and the source and drain electrodes 318 and 320may constitute a thin film transistor T.

[0053] In FIG. 5, a first passivation layer 324 may be formed on thegate insulating layer 314 over an entire surface of the substrate 310 tocover the thin film transistor T and the reflector 322. Then, a blackmatrix 326 may be formed on the first passivation layer 324, especiallycovering the data line 323 and the thin film transistor T, except for aportion of the drain electrode 320. Next, a second passivation layer 328may be disposed on the first passivation layer 324 to cover the blackmatrix 326, wherein the first and second passivation layers 324 and 328may have a drain contact hole that exposes a portion of the drainelectrode 320.

[0054] Then, a first transparent electrode 330 may be formed on thesecond passivation layer 328 within the pixel region P, such that thefirst transparent electrode 330 may contact the drain electrode 320through the drain contact hole and may overlap a portion of the blackmatrix 326. Although not shown, the black matrix 326 may be disposed tocorrespond to a gate electrode (not shown) so that it defines the pixelregion P where a color filter may be disposed, wherein the black matrix326 may function as a border of neighboring color filters. Next, a colorfilter 332 having red, green, or blue colors may be formed on the firsttransparent electrode 330 within the pixel region P. Then, a secondtransparent electrode 334 may be formed on color filter 332 to contactthe first transparent electrode 330 so that the second transparentelectrode 334 may completely cover the color filter 332. Since thesecond transparent electrode 334 may contact the first transparentelectrode 330, the second transparent electrode 334 may electricallycommunicate with the thin film transistor T throughout the firsttransparent electrode 330. The first and second transparent electrodes330 and 334 may constitute a pixel electrode referred to as a sandwichpixel electrode since the color filter 332 may be interposed between thefirst and second transparent electrodes 330 and 334. Accordingly, thepixel region P may be divided into the reflection portion where thereflector 322 is formed and the transmissive portion where the othertransparent layers are formed.

[0055]FIG. 6 is a cross sectional view of another exemplarytransflective liquid crystal display device having a colorfilter-on-thin film transistor structure according to the presentinvention. In FIG. 6, a gate electrode 412 may be formed on a substrate410, and a gate insulating layer 414 may be formed on the substrate 410to cover the gate electrode 412. In addition, a semiconductor layer 416may be disposed on the gate insulating layer 414, especially coveringthe gate electrode 412, and may include a first layer 416 a of intrinsicamorphous silicon and a second layer 416 b of extrinsic amorphoussilicon. The first silicon layer 416 a may be referred to as an activelayer, and a second silicon layer 416 b may be referred to as an ohmiccontact layer.

[0056] Next, source and drain electrodes 420 and 422 may be formed onthe semiconductor layer 416, and a data line 423 may be formed on thegate insulating layer 414 to be connected with the source electrode 420.Then, a reflector 424 may be formed on the gate insulating layer 414within the pixel region P, and may be spaced apart from the drainelectrode 422. Accordingly, an area where the reflector 424 may bedisposed may be defined as a reflective portion. The source electrode420, the drain electrode 422, the reflector 424, and the data line 423may be formed together during the same patterning process using the samemetallic materials.

[0057] In FIG. 6, each of the source electrode 420, the drain electrodes422, and the reflector 424 may have a triple-layered structure. Forexample, the source electrode 420 may include a first metal layer 420 a,a second metal layer 420 b, and a third metal layer 420 c, and the drainelectrode 422 may include a first metal layer 422 a, a second metallayer 422 b, and a third metal layer 422 c. Similarly, the reflector 424may include a first metal layer 424 a, a second metal layer 424 b, and athird metal layer 424 c. The first and third metal layers 420 a, 422 a,424 a, 420 c, 422 c, and 424 c may include metallic material having anexcellent chemical resistance, such as molybdenum (Mo). The second metallayers 420 b, 422 b, and 424 b may include metallic material having lowelectrical resistance, such as aluminum (Al). Thus, each of the sourceelectrode 420, the drain electrodes 422, and the reflector 424 mayinclude the triple-layered structure of Mo—Al—Mo. The first metal layers420 a, 422 a, and 424 a of molybdenum (Mo) may be formed to preventspike phenomenon during formation of the second metal layers 420 b, 422b, and 424 b of aluminum, thereby protecting the underlyingsemiconductor layer 416. The third metal layers 420 c, 422 c, and 424 cof molybdenum (Mo) may be formed to prevent electrochemical reactionbetween the second metal layers of aluminum and a later formedtransparent conductive material, such as indium tin oxide (ITO). Whenforming the source electrode 420, the drain electrode 422, and thereflector 424, first molybdenum (Mo), aluminum (Al) and secondmolybdenum (Mo) may be sequentially deposited and then simultaneouslypatterned to form the Mo—Al—Mo triple-layered structure. Next, anexposed portion of the ohmic contact layer 416 b may be removed toexpose a portion of the active layer 416 a between the source and drainelectrodes 420 and 422, thereby forming a channel on the active layer416 a. Accordingly, the gate electrode 412, the semiconductor layer 416,and the source and drain electrodes 418 and 420 may constitute a thinfilm transistor T.

[0058] In FIG. 6, a first passivation layer 430 may be formed on thegate insulating layer 414 over an entire surface of the substrate 410 tocover the thin film transistor T and the triple-layered reflector 424.Then, a portion of the first passivation layer 430, which is on thereflector 424, may be removed to form an opening 426 to expose the thirdmetal layer 424 c of the reflector 424, and the exposed portion of thethird metal layer 424 c may be removed to expose the underlying secondmetal layer 424 b. Accordingly, the second metal for the second metallayer 424 b, such as aluminum (Al), has a better reflectivity than thethird metal for the third metal layer 424 c, such as molybdenum (Mo).The process of forming the opening 426 may be performed at the same timeas forming a drain contact hole 428 that exposes a portion of the drainelectrode 422 through the first passivation layer 430. The firstpassivation layer 430 and the third metal layer 424 c may besimultaneously patterned throughout the same dry etching process. Thus,an additional process of removing the third metal layer 424 c may not benecessary.

[0059] Next, a black matrix 432 may be formed on the first passivationlayer 430, especially covering the data line 423 and the thin filmtransistor T, except for a portion of the drain electrode 422. Then, asecond passivation layer 434 may be disposed on the first passivationlayer 432 to cover the black matrix 432, wherein the first and secondpassivation layers 430 and 434 together may have the drain contact hole428 that exposes a portion of the drain electrode 422. Next, a firsttransparent electrode 436 may be formed on the second passivation layer434 within the pixel region P to contact the drain electrode 422 throughthe drain contact hole 428, and may overlap a portion of the blackmatrix 432. Although not shown, the black matrix 432 may be disposed tocorrespond to a gate electrode (not shown) so that it defines the pixelregion P where a color filter is disposed, wherein the black matrix 432may function as a border of neighboring color filters. A color filter438 having red, green, or blue colors may be formed on the firsttransparent electrode 436 within the pixel region P, and a secondtransparent electrode 440 may be formed on color filter 438 to contactthe first transparent electrode 436 so that the second transparentelectrode 440 may completely cover the color filter 438. Since thesecond transparent electrode 440 may contact the first transparentelectrode 436, the second transparent electrode 440 may electricallycommunicate with the thin film transistor T throughout the firsttransparent electrode 436. Accordingly, the first and second transparentelectrodes 436 and 440 may constitute a pixel electrode that may bereferred to as a sandwich pixel electrode since the color filter 438 maybe interposed between the first and second transparent electrodes 436and 440. Thus, the pixel region P may be divided into the reflectionportion where the reflector 424 is formed and the transmissive portionwhere the other transparent layers are formed.

[0060]FIGS. 7A to 7K are plan views of exemplary reflective andtransmissive portions within a pixel region of a transflective liquidcrystal display device according to the present invention. In FIG. 7A, apixel region P may include a reflective portion 512 and a transmissiveportion 510, wherein the reflective portion 512 may have a rectangularshape and may be disposed within a central portion of a transmissiveportion 510. In addition, diagonal lines of the transmissive portion 510may exactly correspond to diagonal lines of the reflective portion 512.

[0061] In FIG. 7B, a reflective portion 522 may be disposed within acentral portion of a transmissive portion 520, similar to the reflectiveportion 512 of FIG. 7A. However, the reflective portion 522 may have oneof a rhombic shape and a diamond shape. In addition, the diagonal linesof the transmissive portion 520 may be perpendicular to diagonal linesof the reflective portion 522.

[0062] In FIG. 7C, a reflective portion 532 may be disposed within acentral part of a transmissive portion 530, and may be surrounded by thetransmissive portion 530. The reflective portion 532 may have ahexagonal shape.

[0063] In FIG. 7D, a reflective portion 542 may be disposed within acentral part of a transmissive portion 540, and may be surrounded by thetransmissive potion 540. The reflective portion 542 may have anoctagonal shape.

[0064]FIGS. 7E and 7F show exemplary modifications and variations of thereflective portion of FIG. 7A. In FIGS. 7E and 7F, reflective portions552 and 562 may have rectangular shapes, but may be disposed indifferent locations. In FIG. 7E, the reflective portion 552 may bedisposed at one corner of a transmissive portion 550 so that two sidesof the reflective portion 552 correspond to and contact two sides of thetransmissive portion 550. In FIG. 7F, the reflective portion 562 may bedisposed at one side of a transmissive portion 560 so that one side ofthe reflective portion 562 corresponds to and contacts one side of thetransmissive portion 560. In addition, two sides of therectangular-shaped reflective portion 552 may border on the transmissiveportion 550, as shown in FIG. 7E, and three sides of therectangular-shaped reflective portion 562 may border on the transmissiveportion 560, as shown in FIG. 7F.

[0065]FIGS. 7G to 7I show exemplary reflective portions havingright-angled triangular shapes. In FIG. 7G, a reflective portion 572 maybe disposed inside of a transmissive portion 570, wherein all sides ofthe reflective portion 572 may be surrounded by the transmissive portion570. Accordingly, two sides of the right-angled triangular reflectiveportion 572 may correspond to two sides of the rectangular transmissiveportion 570, but do not contact them.

[0066] In FIG. 7H, one side of a reflective portion 582 may be shapedlike a right-angled triangle that contacts one side of a transmissiveportion 580. However, only one side and the hypotenuse of theright-angled triangular reflective portion 582 may be surrounded by andborder on the transmissive portion 580.

[0067] In FIG. 7I, a right-angled triangular reflective portion 592 maybe disposed at one corner of a rectangular transmissive portion 590 suchthat two sides of the right-angled triangular reflective portion 592 maycontact two sides of the transmissive portion 590. Accordingly, only thehypotenuse of the right-angled triangular reflective portion 582 mayborder on the transmissive portion 590.

[0068]FIGS. 7J and 7K show exemplary reflective portions havingisosceles triangular shapes. In FIG. 7J, a bottom side of an isoscelestriangular reflective portion 612 may correspond to and contact a bottomside of a rectangular transmissive portion 610, and the other two equalsides of the isosceles triangular reflective portion 612 may border onthe transmissive portion 610. In FIG. 7K, a bottom side of an isoscelestriangular reflective portion 622 may correspond to and contact a topside of a rectangular transmissive portion 620, and the other two equalsides of the isosceles triangular reflective portion 622 may border onthe transmissive portion 620.

[0069]FIG. 8 is a cross sectional view of an exemplary transflectiveliquid crystal device having a color filter-on-thin film transistorstructure and buffer patterns according to the present invention. InFIG. 8, a gate electrode 712 may be formed on a substrate 710, and afirst buffer pattern 714 may be formed on the substrate 710 within apixel region P. Accordingly, the first buffer pattern 714 may be spacedapart from the gate electrode 712, and may be disposed within the pixelregion P within a reflective portion where a reflector may be formed.The gate electrode 712 and the first buffer pattern 714 may be formedtogether during the same process step using the same material. Inaddition, a gate insulating layer 716 may be formed on the substrate 710to cover the gate electrode 712 and the first buffer pattern 714.

[0070] Next, a semiconductor layer 718 may be disposed on the gateinsulating layer 716 to cover the gate electrode 712, and a secondbuffer pattern 720 may be disposed on the gate insulating layer 716directly above the first buffer pattern 714. Accordingly, thesemiconductor layer 718 and the second buffer pattern 720 may be formedtogether during the same process step using the same material. Forexample, the semiconductor layer 718 may sequentially include a firstlayer 718 a of intrinsic amorphous silicon and a second layer 718 b ofextrinsic amorphous silicon. Similarly, the second buffer pattern 720may sequentially include a first layer 720 a of intrinsic amorphoussilicon and a second layer 720 b of extrinsic amorphous silicon.Accordingly, the first layer 718 a may be referred to as an activelayer, and a second layer 718 b may be referred to as an ohmic contactlayer.

[0071] Then, source and drain electrodes 722 and 724 may be formed onthe semiconductor layer 718, and a data line 723 may be formed on thegate insulating layer 716 to be connected to the source electrode 722.Next, a reflector 726 may be disposed on the second buffer pattern 720within the reflective portion of the pixel region P, and may be spacedapart from the drain electrode 724. Accordingly, an area where thereflector 726 may be disposed may be defined as the reflective portion.The source electrode 722, the drain electrode 724, the data line 723,and the reflector 726 are formed together during the same patterningprocess using the same metallic material. Next, an exposed portion ofthe ohmic contact layer 718 b between the source and drain electrodes722 and 724 may be removed to expose a portion of the active layer 718a, thereby forming a channel ch on the active layer 718 a. Thus, thegate electrode 712, the semiconductor layer 718, and the source anddrain electrodes 722 and 724 may constitute a thin film transistor T.

[0072] Next, a first passivation layer 728 may be formed on the gateinsulating layer 716 over an entire surface of the substrate 710 tocover the thin film transistor T and the reflector 726. Then, a blackmatrix 730 may be formed on the first passivation layer 728, especiallycovering the data line 723 and the thin film transistor T, except for aportion of the drain electrode 724, and a second passivation layer 732may be disposed on the first passivation layer 728 to cover the blackmatrix 730. In addition, the first and second passivation layers 728 and732 may have a drain contact hole 734 that exposes a portion of thedrain electrode 724. Next, a first transparent electrode 736 may beformed on the second passivation layer 732 within the pixel region P tocontact the drain electrode 724 through the drain contact hole 734, andmay overlap a portion of the black matrix 730. Although not shown, theblack matrix 730 may be disposed to correspond to a gate electrode (notshown) so that it defines the pixel region P where a color filter isdisposed, wherein the black matrix 730 may function as a border ofneighboring color filters. Then, a color filter 738 having red, green,or blue colors may be formed on the first transparent electrode 736within the pixel region P. Next, a second transparent electrode 740 maybe formed on color filter 738 to contact the first transparent electrode736 so that the second transparent electrode 740 may completely coverthe color filter 738. Since the second transparent electrode 740 maycontact the first transparent electrode 736, it may electricallycommunicate with the thin film transistor T. Accordingly, the first andsecond transparent electrodes 736 and 740 may constitute a pixelelectrode 742 referred to as a sandwich pixel electrode since the colorfilter 738 may be interposed between the first and second transparentelectrodes 736 and 740.

[0073] In FIG. 8, the pixel region P may be divided into the reflectionportion where the reflector 726 is disposed and the transmissive portionwhere the other transparent layers are formed. The color filter 738 mayinclude a first portion 738 a that is disposed corresponding to thereflective portion and a second portion 738 b that is disposedcorresponding to the transmissive portion, wherein the first portion 738a may have a first thickness D1 and the second portion 738 b may have asecond thickness D2. Since the first and second buffer patterns 714 and720 may be disposed within the reflective portion under the reflector726, the first thickness D1 may be less than the second thickness D2.For example, the first color filter portion 738 a within the reflectiveportion may be thinner than the second color filter portion 738 b in thetransmissive portion by as much as the thickness of the first and secondbuffer patterns 714 and 720. Thus, it may be possible to minimize lightpath differences between the reflective mode and the transmissive mode.As a result, the color reproduction of the first color filter portion738 a is about equal to that of the second color filter portion 738 b.In addition, light paths of ambient and artificial light may be similar.

[0074]FIG. 9 is a cross sectional view of another exemplarytransflective liquid crystal device having a color filter-on-thin filmtransistor structure and buffer patterns according to the presentinvention. In FIG. 9, a gate electrode 812 may be formed on a substrate810, and a first buffer pattern 814 may be formed on the substrate 810within a pixel region P. The first buffer pattern 814 may be spacedapart from the gate electrode 812, and may be disposed within the pixelregion P in a reflective portion where a reflector may be formed. Thegate electrode 812 and the first buffer pattern 814 may be formedtogether during the same process step using the same material. Inaddition, a gate insulating layer 816 may be formed on the substrate 810to cover the gate electrode 812 and the first buffer pattern 814.

[0075] After forming the gate insulating layer 816, a pure amorphoussilicon layer, an impurity-doped amorphous silicon layer, and a metallayer may be sequentially formed on the gate insulating layer 816. Then,they may be simultaneously patterned to form a semiconductor layer 818,a semiconductor pattern 819, a second buffer pattern 824, a sourceelectrode 820, a drain electrode 822, a data line 821, and a reflector826. The semiconductor layer 818 may be formed on the gate insulatinglayer 816, especially covering the gate electrode 812, and the secondbuffer pattern 824 may be formed on the gate insulating layer 816,especially directly above the first buffer pattern 814. Thesemiconductor pattern 819 may extend from the semiconductor layer 818and may be formed on the gate insulation layer 816, especially directlybeneath the data line 821. The source and drain electrodes 820 and 822may be formed on the semiconductor layer 818, and the data line 821 onthe semiconductor pattern 819 may be connected to the source electrode820 and may have the same pattern shape as the semiconductor pattern819. The reflector 826 may be formed on the second buffer pattern 824and may have the same pattern shape as the second buffer pattern 824.The semiconductor layer 818 may include a sequential arrangement of afirst layer 818 a of intrinsic amorphous silicon and a second layer 818b of extrinsic amorphous silicon. The semiconductor pattern 819 b mayinclude a sequential arrangement of a first layer 819 a of intrinsicamorphous silicon and a second layer 819 of extrinsic amorphous silicon.The second buffer pattern 824 may include a sequential arrangement of afirst layer 824 a of intrinsic amorphous silicon and a second layer 824b of extrinsic amorphous silicon. The first layer 818 a of thesemiconductor layer 818 may be referred to as an active layer, and asecond layer 818 b of the semiconductor layer 818 may be referred to asan ohmic contact layer. Accordingly, an area where the reflector 826 maybe disposed may be defined as the reflective portion, and the sourceelectrode 820, the drain electrode 822, the data line 821, and thereflector 826 may be formed of the same metallic material. Then, anexposed portion of the ohmic contact layer 818 b between the source anddrain electrodes 820 and 822 may be removed to expose a portion of theactive layer 818 a, thereby forming a channel ch on the active layer 818a. Accordingly, the source and drain electrodes 820 and 822 may have thesame pattern shape as the underlying semiconductor layer 818, except forthe channel portion ch. Thus, the gate electrode 812, the semiconductorlayer 818, and the source and drain electrodes 820 and 822 mayconstitute a thin film transistor T.

[0076] In FIG. 9, a first passivation layer 828 may be formed on thegate insulating layer 816 over an entire surface of the substrate 810 tocover the thin film transistor T and the reflector 826. Then, a blackmatrix 830 may be formed on the first passivation layer 828, especiallycovering the data line 821 and the thin film transistor T, except for anedge portion of the drain electrode 724, and a second passivation layer832 may be disposed on the first passivation layer 828 to cover theblack matrix 830. Then, the first and second passivation layer 828 and832 may be simultaneously patterned to form a first opening 834 and asecond opening 836. The first opening 834 may expose the edge portion ofthe drain electrode 822, and the second opening 836 may expose thesubstrate 810 in the transmissive portion of the pixel region P wherethe reflector 826 is not disposed.

[0077] Next, a first transparent electrode 838 may be formed within thepixel region P to contact the edge portion of the drain electrode 822through the first opening 834, and may overlap a portion of the blackmatrix 830. Although not shown, the black matrix 830 may be disposed tocorrespond to a gate electrode (not shown) so that it defines the pixelregion P where a color filter is disposed, wherein the black matrix 830may function as a border of neighboring color filters. Next, a colorfilter 842 having red, green, or blue colors may be formed on the firsttransparent electrode 838 within the pixel region P. Then, a secondtransparent electrode 846 may be formed on color filter 842 to contactthe first transparent electrode 838 so that the second transparentelectrode 846 may completely cover the color filter 842. Since thesecond transparent electrode 846 may contact the first transparentelectrode 838, it may electrically communicate with the thin filmtransistor T. Accordingly, the first and second transparent electrodes838 and 846 may constitute a pixel electrode 848 that may be referred toas a sandwich pixel electrode since the color filter 842 may beinterposed between the first and second transparent electrodes 838 and846.

[0078] Accordingly, the pixel region P may be divided into thereflection portion where the reflector 826 and the buffer patterns 814and 824 are disposed and the transmissive portion where the reflector826 and the buffer patterns 814 are not formed. The color filter 842 mayinclude a first portion 842 a that may correspond to the reflectiveportion and a second portion 842 b that may correspond to thetransmissive portion. In addition, the first portion 842 a may have afirst thickness D1 and the second portion 842 b may have a secondthickness D2. Since the first and second buffer patterns 814 and 824 andthe patterned insulators 816, 828, and 832 may be disposed in thereflective portion, the first thickness D1 may be less than the secondthickness D2. For example, the first color filter portion 842 a in thereflective portion may be thinner than the second color filter portion842 b in the transmissive portion by as much as the thickness of thefirst and second buffer patterns 714 and 720 and the patternedinsulators 816, 828, and 832. Furthermore, since the gate insulatinglayer 816 and the first and second passivation layers 828 and 832 may beremoved from the transmissive portion, the second thickness D2 may besignificantly larger than the second thickness D2 in FIG. 8.Accordingly, it may be possible to minimize light path differences inthe reflective mode and in the transmissive mode. Thus, light paths ofambient and artificial light may be the same to each.

[0079]FIGS. 10A to 10E are cross sectional views of another exemplarytransflective LCD devices each having a color filter-on-thin filmtransistor structure and buffer patterns according to the presentinvention. In FIGS. 10A to 10E, each exemplary transflective LCD devicemay have the thin film transistor, the buffer patterns, and thereflector as those of FIG. 9. Thus, the detailed descriptions for thoseelements are omitted.

[0080] In FIG. 10A, a thin film transistor T may be formed on asubstrate 910, and buffer patterns and a reflector 926 may be formed onand over the substrate 910 in a reflective portion of a pixel region P.Then, a passivation layer 938 may be formed on the thin film transistorT to cover the thin film transistor T, except for a portion of a drainelectrode 922. In addition, the passivation layer 938 may be formed inthe reflective portion to cover the reflector 926. Accordingly, a gateinsulating layer 916 and the passivation layer 938 may not exist in atransmissive portion of the pixel region P, but the gate insulatinglayer 916 and the passivation layer 938 may be disposed in the thin filmtransistor T and in the reflective portion. For example, the gateinsulating layer 916 and the passivation layer 938 may have an opening936 that exposes an edge of the drain electrode 922 and exposes thesubstrate 910 in the transmissive portion of the pixel region P.

[0081] Next, a color filter 942 may be disposed over an entire surfaceof the substrate 910 and may have a drain contact hole 940, wherein thecolor filter 942 may have one of red, green, and blue colors in eachpixel region P. Then, a transparent pixel electrode 944, which maycontact the drain electrode 922 through the drain contact hole 940, maybe formed on the color filter 942, and a black matrix 946 may be formedabove the color filter 942 to cover the thin film transistor T. Althoughnot shown, the black matrix 946 may also cover data and gate lines (notshown).

[0082] In contrast to the exemplary transflective LCD device of FIG. 9,the exemplary transflective LCD device of FIG. 10A may not include anadditional passivation layer and an additional transparent electrode.Accordingly, the exemplary transflective LCD device of FIG. 10A may befabricated through a simplified fabrication process.

[0083] In FIG. 10B, a thin film transistor T may be formed on asubstrate 1010, and buffer patterns and a reflector 1026 may be formedon and over the substrate 1010 especially within a reflective portion ofa pixel region P. Then, a passivation layer 1038 may be formed on thethin film transistor T to cover the thin film transistor T, except foran edge portion of a drain electrode 1022. In addition, the passivationlayer 1038 may be formed in the reflective portion to cover thereflector 1026. Although a gate insulating layer 1016 and thepassivation layer 1038 may not exist in a transmissive portion of thepixel region P, the gate insulating layer 1016 and the passivation layer1038 may be disposed in the thin film transistor T and in the reflectiveportion. For example, the gate insulating layer 1012 and the passivationlayer 1038 may have an opening 1036 that exposes an edge of the drainelectrode 1022 and exposes the substrate 1010 in the transmissiveportion of the pixel region P.

[0084] Next, a black matrix 1040 may be formed on the passivation layer1038, especially above the thin film transistor T. Although not shown,the black matrix 1040 may correspond to positions of the data and gatelines (not shown) so that it defines the pixel region P where a colorfilter is disposed, wherein the black matrix 1040 may function as aborder of neighboring color filters. Next, a color filter 1044 may bedisposed over an entire surface of the substrate 1010, except for theblack matrix 1040, and may have a drain contact hole 1042. The colorfilter 1044 may have one of red, green, and blue colors within eachpixel region P. Then, a transparent pixel electrode 1046, which maycontact the drain electrode 1022 through the drain contact hole 1042,may be formed on the color filter 1044, wherein the transparent pixelelectrode 1046 may overlap a portion of the black matrix 1040 so that itcompletely covers the color filter 1044.

[0085] In FIG. 10B, since the black matrix 1040 may be formed of amaterial including chromium (Cr), an additional passivation layer maynot be required, as compared to the exemplary transflective LCD deviceof FIG. 9. Moreover, since the color filter 1044 may have the draincontact hole 1042 therein, the transparent pixel electrode 1046 maydirectly contact the drain electrode through the drain contact hole1042. Accordingly, an additional transparent electrode may not benecessary, as compared to the exemplary transflective LCD device of FIG.9. Thus, manufacturing process of the exemplary transflective LCD deviceof FIG. 10B may be simplified.

[0086] The exemplary transflective LCD device of FIG. 10C is similar tothe exemplary transflective LCD device of FIG. 10A, except aplanarization layer may be formed on a color filter. In FIG. 10C, a thinfilm transistor T may be formed on a substrate 1110, and buffer patternsand a reflector 1126 may be formed on and over the substrate 1110 in areflective portion of a pixel region P. Next, a passivation layer 1138may be formed on the thin film transistor T to cover the thin filmtransistor T, except for a portion of a drain electrode 1122. Inaddition, the passivation layer 1138 may be formed in the reflectiveportion to cover the reflector 1126. Although a gate insulating layer1116 and the passivation layer 1138 may not exist in a transmissiveportion of the pixel region P, the gate insulating layer 1116 and thepassivation layer 1138 may be disposed in the thin film transistor T andin the reflective portion. For example, the gate insulating layer 1116and the passivation layer 1138 may have an opening 1136 that exposes anedge of the drain electrode 1122 and exposes the substrate 1110 in thetransmissive portion of the pixel region P.

[0087] Next, a color filter 1142 and a planarization layer 1144 may besequentially disposed over an entire surface of the substrate 1110, andmay both have a drain contact hole 1140 that exposes the edge portion ofthe drain electrode 1122. The color filter 1142 may have one of red,green, and blue colors in each pixel region P. Then, a transparent pixelelectrode 1146, which may contact the drain electrode 1122 through thedrain contact hole 1140, may be formed on the planarization layer 1144.Accordingly, the planarization layer 1144 may function to planarize thesurface of the color filter 1142 and may enhance adhesion of thetransparent pixel electrode 1146. Next, a black matrix 1148 may beformed above the planarization layer 1144 to cover the thin filmtransistor T. Although not shown, the black matrix 1148 may also coverdata and gate lines (not shown).

[0088] The exemplary transflective LCD device of FIG. 10D may be similarto the exemplary transflective LCD device of FIG. 10B, except aplanarization layer may be formed between the color filter and atransparent pixel electrode. In FIG. 10D, a thin film transistor T maybe formed on a substrate 1210, and buffer patterns and a reflector 1226may be formed on and over the substrate 1210 within a reflective portionof a pixel region P. Next, a passivation layer 1238 may be formed on thethin film transistor T to cover the thin film transistor T, except foran edge portion of a drain electrode 1222. In addition, the passivationlayer 1238 may be formed in the reflective portion to cover thereflector 1226. Although a gate insulating layer 1216 and thepassivation layer 1238 may not exist in a transmissive portion of thepixel region P, the gate insulating layer 1216 and the passivation layer1238 may be disposed within the thin film transistor T and in thereflective portion. For example, the gate insulating layer 1212 and thepassivation layer 1238 may have an opening 1236 that exposes an edge ofthe drain electrode 1222 and exposes the substrate 1210 in thetransmissive portion of the pixel region P.

[0089] Next, a black matrix 1240 may be formed on the passivation layer1238, especially above the thin film transistor T. Although not shown,the black matrix 1240 may correspond in position to data and gate lines(not shown) so that it defines the pixel region P where a color filteris disposed, wherein the black matrix 1240 may function as a border ofneighboring color filters. Next, the color filter 1242 may be disposedover an entire surface of the substrate 1210, except for the blackmatrix 1240, and a planarization layer 1246 may be formed over an entiresurface of the substrate 1210 to cover the black matrix 1240 and thecolor filter 1242. In addition, the color filter 1242 and theplanarization layer 1244 may have a drain contact hole 1244 that mayexpose the edge portion of the drain electrode 1222. The color filter1242 may have one of red, green, and blue colors in each pixel region P.Next, a transparent pixel electrode 1250, which may contact the drainelectrode 1222 through the drain contact hole 1244, may be formed on theplanarization layer 1246. In addition, the transparent pixel electrode1250 may overlap a portion of the black matrix 1240 so that it maycompletely cover the color filter 1242.

[0090]FIGS. 11A to 11H are cross sectional views of an exemplaryfabrication process of a transflective liquid crystal display deviceaccording to the present invention. In FIG. 11A, a first metal layer maybe formed on a substrate 1310, and then patterned using a first maskprocess, thereby forming a gate electrode 1312 and a first bufferpattern 1314. The gate electrode 1312 and the first buffer pattern 1314may be spaced apart from each other, and the first metal layer mayinclude a metal having low specific resistance value, such as aluminum(Al) or an aluminum alloy.

[0091] In FIG. 11B, a first insulation layer (a gate insulation layer),a pure amorphous silicon, a doped amorphous silicon, and a second metallayer may be sequentially formed over the substrate 1310 to cover thegate electrode 1312 and the first buffer pattern 1314. Then, the secondmetal layer, the doped amorphous silicon layer, and the pure amorphoussilicon layer may be simultaneously patterned using a second maskprocess, thereby forming a plurality of metal patterns and a pluralityof silicon patterns. During the patterning process, the first insulationlayer may not be patterned, thereby forming a gate insulation layer1315. The plurality of silicon patterns over the gate electrode 1312 maybecome a semiconductor layer 1316 comprising an active layer 1316 a ofpure amorphous silicon and an ohmic contact layer 1316 b of dopedamorphous silicon. The plurality of patterned silicon layers over thefirst buffer pattern 1314 may become a second buffer pattern 1324 havinga first layer 1324 a of pure amorphous silicon and a second layer 1324 bof doped amorphous silicon. The patterned second metal may become a dataline 1322, a source electrode 1318, a drain electrode 1320, and areflector 1326, wherein the source and drain electrodes 1318 and 1320may be disposed on the ohmic contact layer 1316 b. In addition, the dataline 1322 may extend from and may be connected to the source electrode1318, and the reflector 1326 may be disposed on the second layer 1324 bof the second buffer pattern 1324. When patterning the silicon layersand the second metal layer, a half tone mask having a half lighttransmitting portion, such as slits, may be adopted so that the sourceand drain electrodes 318 and 320 may be separated from each other.Accordingly, a portion of the ohmic contact layer 1316 b between thesource and drain electrodes 1318 and 1320 may be eliminated using thesource and drain electrodes 1318 and 1320 as masks, thereby forming achannel (ch) on the active layer 1316 a.

[0092] Meanwhile, a silicon pattern 1317 comprising a first layer 1317 aof pure amorphous silicon and a second layer 1317 b of doped amorphoussilicon may be disposed beneath the data line 1322, and may have thesame planar shape as the data line 1322. Since the second metal layermay become the reflector 1326 by way of patterning, the second metallayer may have good chemical resistance and great light reflectivity.For example, a double layer structure may include a first aluminum layerand a second metal layer may include at least one of molybdenum (Mo),tungsten (W), nickel (Ni), and titanium (Ti).

[0093] In FIG. 11B, the gate electrode 1312, the semiconductor layer1317, the source electrode 1318, and the drain electrode 1320 mayconstitute a thin film transistor T. In a pixel region P that may bedefined by the gate and data lines, an area including the reflector 1326and the first and second buffer patterns 1314 and 1324 may become areflective portion, and the rest area, except for the reflective portionthat may become a transmissive portion.

[0094] In FIG. 11C, a second insulation layer (a first passivationlayer) 1328 may be formed over the entire surface of the substrate 1310to cover the thin film transistor T and the reflector 1326.

[0095] In FIG. 11D, a light shielding material may be formed on thefirst passivation layer 1328, and then patterned using a third maskprocess, thereby forming a black matrix 1330 covering the thin filmtransistor, except for a portion of the drain electrode 1320.

[0096] In FIG. 11E, a third insulation layer (a second passivationlayer) 1336 may be formed over the entire surface of the substrate 1310to cover the black matrix 1330. Then, the first and second passivationlayers 1328 and 1336 and the gate insulation layer 1315 may besimultaneously patterned using a fourth mask process to form an opening1334 that exposes an edge portion of the drain electrode 1320. Theopening 1334 may also expose the substrate 1310 in the transmissiveportion of the pixel region P.

[0097] In FIG. 11F, a first transparent conductive layer 1338 may beformed over an entire surface of the substrate 1310 to cover thepatterned second passivation layer 1336, thereby contacting the exposedportion of the drain electrode 1320. Further, the first transparentconductive layer 1338 may contact the substrate 1310 within thetransmissive portion.

[0098]FIG. 11G shows an exemplary step of forming a color filter layer1340 using a color resin. In FIG. 11G, the color resin may be firstformed on the first transparent conductive layer 1338, and thenpatterned using a fifth mask process. Accordingly, the color filter 1340may be disposed within the pixel region P. In addition, the black matrix1330 may function as a barrier that separates the color filter from thecolor filter of the neighboring pixels. For example, the black matrix1338 may border the neighboring color filters 1340.

[0099] The color filter 1340 may have one of red, green, and bluecolors, and may be divided into two portions, such as a first portion1340 a and a second portion 1340 b. The second portion 1340 b may bedisposed in the reflective portion where the first buffer pattern 1314,the patterned gate insulation layer 1315, the second buffer pattern1324, the reflector 1326, and the patterned first and second passivationlayers 1328 and 1336 may be disposed. The first portion 1340 a of thecolor filter may be disposed in the transmissive portion of the pixelregion P and over the edge portion of the drain electrode. The firstportion 1340 a may have a first thickness D11 and the second portion1340 b may have a second thickness D22, wherein the first thickness D11may be significantly larger than the second thickness D22 due a lack ofbuffer patterns and insulation layers beneath the first portion 1340 a.Thus, no light path differences exist between artificial light from thebacklight device and ambient light from the surroundings, therebyincreasing color reproduction of the color filter 1340.

[0100] In FIG. 11H, a second transparent conductive layer may be formedover the entire surface of the substrate 1310 to cover the color filter1340, and may contact the exposed portion of the first transparentconductive layer. Then, the first and second transparent conductivelayers may be simultaneously patterned using a sixth mask process toform first and second transparent pixel electrodes 1346 and 1348 in thepixel region P. During the patterning process of the first and secondtransparent conductive layers, portions above the black matrix may beremoved. Accordingly, the first and second transparent pixel electrodes1346 and 1348 may constitute a pixel electrode 1350 that may be referredto as a sandwich pixel electrode since the color filter layer 1340 maybe interposed between the first and second transparent pixel electrodes1346 and 1348. In addition, the first and second transparent pixelelectrodes 1346 and 1348 are formed of a transparent conductivematerial, such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0101] According to the present invention, since the reflector may beformed during the formation of a metal pattern of the thin filmtransistor, a process of forming the reflector may be omitted. Inaddition, since the buffer patterns formed during the formation of thethin film transistor may be disposed beneath the reflector, it may bepossible to reduce differences of color reproduction in the reflectiveportion and in the transmissive portion, thereby improving the displayquality of the transflective liquid crystal display device. Furthermore,since the reflector may be designed to have various geometrical shapeswithin the pixel region, it may be possible to control the ratio of thereflective portion to the transmissive portion.

[0102] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the transflective liquidcrystal display device having color filter-on-thin film transistor (cot)structure of the present invention without departing from the spirit orscope of the inventions. Thus, it is intended that the present inventioncovers the modifications and variations of this invention provided theycome within the scope of the appended claims and their equivalents.

What is claimed is:
 1. A transflective liquid crystal display device,comprising: a thin film transistor disposed at a corner of a pixelregion, the thin film transistor including a gate electrode, asemiconductor layer, a source electrode, and a drain electrode; areflector disposed in the pixel region and spaced apart from the thinfilm transistor, the reflector formed of the same material as one of thegate, source, and drain electrodes; a color filter disposed within thepixel region, the color filter having one of red, green, and bluecolors; a black matrix over the thin film transistor along color filterborders of adjacent pixel regions; and a pixel electrode formed of atransparent conductive material adjacent to the color filter, the pixelelectrode having a first end portion contacting the drain electrode ofthe thin film transistor; wherein the pixel region is divided into areflective portion including the reflector and a transmissive portionabsent of the reflector.
 2. The device according to claim 1, wherein thereflector is formed of the same material as the gate electrode, and isformed at the same time of forming the gate electrode.
 3. The deviceaccording to claim 2, wherein the reflector and the gate electrode havedouble-layered structures including a second layer on a first layer, andthe second layer of the reflector is partially removed to expose anunderlying portion of the first layer of the reflector.
 4. The deviceaccording to claim 3, wherein the first layer includes aluminum and thesecond layer includes molybdenum.
 5. The device according to claim 1,wherein the reflector is formed of the same material as the source anddrain electrodes, and is formed at the same time when forming the sourceand drain electrodes.
 6. The device according to claim 5, wherein eachof the source electrode, the drain electrode, and the reflector includetriple-layered structures that comprise: a first layer; a second layeron the first layer; and a third layer on the second layer; wherein thethird layer of the reflector is partially eliminated to expose anunderlying portion of the second layer.
 7. The device according to claim6, wherein the first layer includes molybdenum, the second layerincludes aluminum, and the third layer includes molybdenum.
 8. Thedevice according to claim 1, wherein the transmissive portion surroundsthe reflective portion.
 9. The device according to claim 8, wherein thetransmissive and reflective portions have a rectangular shape, anddiagonal lines of the transmissive portion directly correspond todiagonal lines of the reflective portion.
 10. The device according toclaim 8, wherein the transmissive and reflective portions have arectangular shape and diagonal lines of the transmissive portion aredirectly perpendicular to diagonal lines of the reflective portion. 11.The device according to claim 8, wherein the reflective portion has ahexagonal shape and is disposed in a central part of the transmissiveportion.
 12. The device according to claim 8, wherein the reflectiveportion has an octagonal shape and is disposed in a central part of thetransmissive portion.
 13. The device according to claim 1, wherein thereflective potion has a rectangular shape and is disposed at one cornerof the transmissive portion, and two sides of the reflective portioncorrespond and contact to two sides of the transmissive portion.
 14. Thedevice according to claim 1, wherein the reflective potion has arectangular shape and is disposed at one side of the transmissiveportion, and one side of the reflective portion corresponds and contactsone side of the transmissive portion.
 15. The device according to claim1, wherein the reflective portion has a right-angled triangular shapeand is surrounded by the transmissive portion.
 16. The device accordingto claim 1, wherein the reflective portion has a right-angled triangularshape, and one side of the reflective portion contacts one side of thetransmissive potion and a second side and hypotenuse of the reflectiveportion border the transmissive portion.
 17. The device according toclaim 1, wherein the reflective portion has a right-angled triangularshape, and two sides of the reflective portion correspond and contacttwo sides of the transmissive potion so that hypotenuse of thereflective portion borders on the transmissive portion.
 18. The deviceaccording to claim 1, wherein the reflective portion has an isoscelestriangular shape, and a bottom side of the reflective portioncorresponds and contacts one side of the transmissive portion so thattwo equal sides of the reflective portion border on the transmissiveportion.
 19. The device according to claim 1, further comprising apassivation layer between the black matrix and the color filter.
 20. Thedevice according to claim 1, wherein the pixel electrode includes afirst transparent pixel electrode and a second transparent pixelelectrode, the first transparent pixel electrode is disposed between theblack matrix and the color filter and contacts the drain electrode, andthe second transparent pixel electrode is on the pixel electrode tocontact the first transparent pixel electrode.
 21. The device accordingto claim 1, further comprising a passivation layer covering both thethin film transistor and the reflector.
 22. A transflective liquidcrystal display device, comprising: a substrate; a gate electrodedisposed in a thin film transistor region on the substrate; a firstbuffer pattern disposed in a pixel region on the substrate and spacedapart from the gate electrode; a gate insulation layer formed on thesubstrate to cover the gate electrode and the first buffer pattern; asemiconductor layer on the gate insulation layer over the gateelectrode; a second buffer pattern formed of the same material as thesemiconductor layer and formed during the same time as formation ofsemiconductor layer, the second buffer pattern disposed above the firstbuffer pattern in the pixel region; source and drain electrodes formedon the semiconductor layer and space apart from each other; a reflectoron the second buffer pattern, the reflector formed of the same materialas the source and drain electrodes; a color filter disposed within thepixel region and having one of red, green, and blue colors; a blackmatrix formed above a thin film transistor in the thin film transistorregion, the thin film transistor includes the gate electrode, thesemiconductor layer, and the source and drain electrodes, the blackmatrix covering the thin film transistor except for a portion of thedrain electrode and bordering adjacent color filters of neighboringpixel regions; and a pixel electrode disposed in the pixel region andformed of a transparent conductive material, the pixel electrodeadjacent to the color filter and having a first end portion contactingthe drain electrode of the thin film transistor; wherein the pixelregion is divided into a reflective portion that includes the reflectorand a transmissive portion that is absent of the reflector, the colorfilter has a first thickness in the transmissive portion and a secondthickness in the reflective portion, and the first thickness is largerthan the second thickness.
 23. The device according to claim 22, furthercomprising a passivation layer between the black matrix and the colorfilter, wherein the passivation layer has an opening that exposes aportion of the drain electrode.
 24. The device according to claim 22,wherein the pixel electrode includes a first transparent pixel electrodeand a second transparent pixel electrode, the first transparent pixelelectrode is disposed between the black matrix and the color filter andcontacts the drain electrode, and the second transparent pixel electrodeis on the pixel electrode to contact the first transparent pixelelectrode.
 25. The device according to claim 22, further comprising apassivation layer covering both the thin film transistor and thereflector.
 26. A transflective liquid crystal display device,comprising: a substrate; a gate electrode disposed in a thin filmtransistor region on the substrate; a first buffer pattern disposed in apixel region on the substrate and spaced apart from the gate electrode;a gate insulation layer formed on the substrate to cover the gateelectrode and the first buffer pattern; a semiconductor layer on thegate insulation layer over the gate electrode; a second buffer patterndisposed above the first buffer pattern in the pixel region and formedof the same material as the semiconductor layer and formed during thesame time as the semiconductor layer; source and drain electrodes formedon the semiconductor layer, the source and drain electrodes have thesame planar shape with the semiconductor layer except for a spacebetween the source and drain electrodes; a reflector on the secondbuffer pattern, the reflector is formed of the same material as thesource and drain electrodes and has the same planar shape as the secondbuffer pattern; a color filter disposed within the pixel region, andhaving one of red, green, and blue colors; a black matrix formed above athin film transistor in the thin film transistor region, the thin filmtransistor includes the gate electrode, the semiconductor layer, and thesource and drain electrodes, the black matrix covering the thin filmtransistor except for a portion of the drain electrode and bordersadjacent color filters of the neighboring pixel regions; a passivationlayer covering the thin film transistor and the reflector, thepassivation layer exposing an edge portion of the drain electrode; and apixel electrode disposed in the pixel region and formed of a transparentconductive material, the pixel electrode adjacent to the color filterand contacting the edge portion of the drain electrode of the thin filmtransistor, wherein the pixel region is divided into a reflectiveportion having the reflector and a transmissive portion absent of thereflector, the color filter has a first thickness in the transmissiveportion and a second thickness in the reflective portion, and the firstthickness is larger than the second thickness.
 27. The device accordingto claim 26, further comprising an additional passivation layer betweenthe black matrix and the color filter, the additional passivation layerhas an opening that exposes the edge portion of the drain electrode andthe substrate in the transmissive portion.
 28. The device according toclaim 26, wherein the pixel electrode includes a first transparent pixelelectrode and a second transparent pixel electrode, the firsttransparent pixel electrode is disposed between the black matrix and thecolor filter and contacts the drain electrode, and the secondtransparent pixel electrode is on the pixel electrode to contact thefirst transparent pixel electrode.
 29. A transflective liquid crystaldisplay device, comprising: a substrate; a gate electrode disposed in athin film transistor region on the substrate; a first buffer patterndisposed in a pixel region on the substrate and spaced apart from thegate electrode; a gate insulation layer formed on the substrate to coverthe gate electrode and the first buffer pattern; a semiconductor layeron the gate insulation layer over the gate electrode; a second bufferpattern formed of the same material as the semiconductor layer andformed at the same time as the semiconductor layer, the second bufferpattern disposed above the first buffer pattern in the pixel region;source and drain electrodes formed on the semiconductor layer and spaceapart from each other, the source and drain electrodes have the sameplanar shape with the semiconductor layer except for a space between thesource and drain electrodes; a reflector on the second buffer pattern,the reflector is formed of the same material as the source and drainelectrodes and has the same planar shape as the second buffer pattern; athin film transistor disposed in the thin film transistor region, thethin film transistor including the gate electrode, the semiconductorlayer, and the source and drain electrodes; a passivation layer coveringthe thin film transistor and the reflector, the passivation layerexposing an edge portion of the drain electrode; and a color filterdisposed over an entire surface of the substrate on the passivationlayer, the color filter having one of red, green, and blue colors andhaving a drain contact hole exposing the edge portion of the drainelectrode; and a pixel electrode formed of a transparent conductivematerial and disposed over the color filter in the pixel region, thepixel electrode contacting the edge portion of the drain electrodethrough the drain contact hole, wherein the pixel region is divided intoa reflective portion having the reflector and a transmissive portionabsent of the reflector, the color filter has a first thickness in thetransmissive portion and a second thickness in the reflective portion,and the first thickness is larger than the second thickness.
 30. Thedevice according to claim 29, further comprising a black matrix abovethe thin film transistor filter between the color filters of neighboringpixel regions.
 31. The device according to claim 29, further comprisinga black matrix above the pixel electrode covering the thin filmtransistor.
 32. The device according to claim 29, further comprising aplanarization layer between the color filter, the pixel electrode, and ablack matrix on the planarization layer, the planarization layer has acontact hole corresponding to the drain contact hole, and the blackmatrix overlaps the thin film transistor.
 33. The device according toclaim 29, further comprising a black matrix above the thin filmtransistor filter between the adjacent color filters of neighboringpixel regions, and a planarization layer covering both the black matrixand the color filter.
 34. A method of fabricating a transflective liquidcrystal display device, comprising: forming a gate electrode and a firstbuffer pattern on a substrate using a first mask process; forming a gateinsulation layer on the substrate to cover the gate electrode and thefirst buffer pattern; forming a pure amorphous silicon layer, a dopedamorphous silicon layer, and a metal layer in sequence on the gateinsulation layer; patterning the pure amorphous silicon layer, the dopedamorphous silicon layer, and the metal layer simultaneously using asecond mask process to form a semiconductor layer over the gateelectrode, source and drain electrodes on the semiconductor layer, asecond buffer pattern over the first buffer pattern, and a reflector onthe second buffer pattern; forming a first passivation layer on the gateinsulation layer to cover the source and drain electrodes and thereflector; forming a black matrix on the first passivation layer tocover the gate electrode, the source electrode, and the drain electrodeexcept for an edge portion of the drain electrode; forming a secondpassivation layer on the first passivation layer to cover the blackmatrix; patterning the first and second passivation layers and the gateinsulation layer to form an opening that exposes the edge portion of thedrain electrode and portions of the substrate; forming a firsttransparent conductive layer over an entire surface of the substrate,the first transparent conductive layer contacting the exposed edgeportion of the drain electrode and the exposed portion of the substrate;forming a color filter on the first transparent conductive layer in apixel region to cover the reflector, the color filter having one of red,green, and blue colors; forming a second transparent conductive layer onthe color filter and on an exposed portion of the first transparentconductive layer; patterning the first and second transparent conductivelayers simultaneously to form first and second transparent pixelelectrodes between where the color filter is interposed.
 35. The methodaccording to claim 34, wherein the second mask process uses a half tonemask having a half light transmitting portion.
 36. The method accordingto claim 34, wherein the gate electrode, the semiconductor layer, andthe source and drain electrodes constitute a thin film transistor. 37.The method according to claim 34, wherein the source and drainelectrodes have the same planar shape as the semiconductor layer exceptfor a space between the source and drain electrodes.
 38. The methodaccording to claim 34, wherein the reflector has the same planar shapeas the second buffer pattern.
 39. The method according to claim 34,wherein a first area where the reflector is disposed defines areflective portion and a second area where the first transparent pixelelectrode contacts the substrate defines a transmissive portion.
 40. Themethod according to claim 39, wherein the color filter has a firstthickness in the transmissive portion and a second thickness in areflective portion, and the first thickness is larger than the firstthickness.